Raw materials in this experiment are zinc oxide(ZnO), selenium powder(Se) and sodium borohydride (NaBH₄). ZnO/ZnSe core/shell nanowires with different temperatures(50,70,90 ℃) were fabricated by dip-coating method. And structure, morphology and photocatalytic properties of these samples will be studied in detail by transmission electron microscope(TEM), Raman spectroscopy (RAMAN), UV-Vis spectrophotometer (UV-Vis) and photocatalytic properties test.The results show that: the reaction temperatures of samples are higher, ZnSe particles attached to the surface of ZnO are denser, core-shell structure of nanowires is more obvious, the degradation rate of these samples is more rapid and the effect of degrading of ZnO/ZnSe core/shell nanowires is more significant in the Halogen lamp irradiation. However, 70℃ is the optimum reaction temperature to fabricate ZnO/ZnSe core/shell nanowires when convenience of fabrication process and environmental protection are taken into consideration.

Surface modification is one of the core technologies in the field of biomedical materials, its fundamental purpose is to make the surface of the biological material has better biocompatibility. Presently, various surface modification has been developed by different groups, and different methods of surface modification is selected in terms of the application fields and the faced problems of biomaterials, including reducing protein adsorption and coagulation, controlling cell adhesion,growth and differentiation, and improving the mechanical properties, The surface modification technology of cardiovascular biomaterials mainly focus on improving the blood compatibility of the materials and the endothelial cell compatibility, and can be further expanded to tissue engineering and regenerative medicine. In this paper, the research status of cardiovascular biomaterials, the surface biomodification methods and the surface modification technology for different purposes are reviewed, in order to provide important reference for the design and development of a new generation of cardiovascular implantable medical devices.

Thermosetting polyimide resins were polymer materials with repetitive structure (—C—N—C—). They could not be dissolved and melted after cured, but just be moulded by one-time thermoforming. There were three kinds of moulding process for PI: hot press moulding, autoclave moulding, and cold press and sintering, and the moulding temperature, pressure and time were changing by different raw monomer. These three kinds of moulding process had merits and demerits respectively. There were phenomenon of non-uniform heating on PI product, because the moulding process belong to external heating radiation. A new idea of moulding process for thermosetting PI by promoting chain movement with electromagnetic wave was put forward.

Graphene has attracted tremendous attention from researchers due to its excellent electrical, thermal, mechanical properties, as well as high optical transparency and large specific surface area, etc. Especially in 2004, stable graphene was successfully gained, it leads to a high tide for the research. To get the graphene which is low cost, large area, high quality and can be applied to practical production is the aim of the researchers. This paper reviews some modified or new preparation methods of the graphene and its potential applications in recent years, from which we can see the huge development potential of the graphene.

Metal hydride hydrogen compression technology has the advantages of good safety, no moving parts, and the ability to use low-grade waste heat. However, this technology has high requirements for the hydrogen sorption plateau pressure, plateau slope, hysteresis of hydrogen storage alloys. In this paper, the influence of the addition of alloying elements on the hydrogen compression properties of BCC structure vanadium-based alloys is studied. The V₇₅Ti₂₀M₅ (M=V, Ti, Cr or Zr) hydrogen compression alloys were prepared by the arc melting method, using volume adsorption method to determinate the PCT curve and kinetic properties, and the plateau slope, hysteresis effect, hydrogen compression ratio and hydrogen reaction rate of the alloy PCT curve were obtained by calculation to compare the hydrogen compression properties of alloys. The results show that the reversible hydrogen storage capacity of V₇₅Ti₂₀Cr₅ alloy is 1.05 wt%. Compared with V₇₅Ti₂₅ alloy, the hydrogen compression rate is significantly improved, and V₇₅Ti₂₀Zr₅ significantly reduces the reversible hydrogen storage, hydrogen compression ratio and hydrogen compression rate of the alloy.

Material corrosion and anti-corrosion have always been an indispensable part in material development and application. Epoxy resin is widely used for anti-corrosion due to its excellent anti-corrosion ability, adhesion and mechanical strength. However, with the rapid development of the coatings field, some shortcomings of epoxy resins have been exposed: brittleness, insufficient heat resistance and the existence of holes. In view of these shortcomings, this article summarizes the various modifications of epoxy resin coatings made by domestic and foreign researchers in recent years. First of all, this article summarizes the current mainstream research directions at home and abroad from the selection of modified materials and the innovation of research methods. For the existence of pores, nano micro-inorganic substances with special functions (such as wear resistance, temperature resistance, acid and alkali resistance, etc.) are adopted. Due to poor heat resistance and high brittleness, the epoxy resin has been modified at the molecular level to improve the relevant performance or make the epoxy resin have unique functions. For special applications, bionic design is used to make coatings have antifouling effects, such as hydrophobicity and sterilization, and no pollution to the environment. Secondly, this article also introduces the best anti-corrosion effect of each improved method, and compares the advantages and disadvantages of each method. Finally, the future development trend of epoxy resin anticorrosive coatings is discussed, and the feasibility of various modification schemes in future applications is analyzed.

Super-hydrophobic is an important surface properties of the plants and animals surface in nature. It has great potential because of its high contact angle and low roll angle, with self-cleaning and reconciliations interfacial adhesion and friction, and it has caused widespread concern in surface engineering and precision engineering. This paper summarizes the development of superhydrophobic theoretical models in recent years and the main factors affecting of superhydrophobic property, starting with the classical theory of energy, application Young's equation, the theoretical models of Wenzel and Cassie-Baxter, and their transition condition to explain the formation mechanism of superhydrophobic surface, and discussing the contact angle of hysteresis theory and the theory of the contact line in superhydrophobic surfaces; then summary of the geometric topology structure of the surface and its parameters effect of super hydrophobic properties based on Wenzel and Cassie-Baxter two theoretical model; final analysis the prospects for superhydrophobic future.

N doped TiO₂ nanotube arrays were prepared by anodic oxidation combined with solution processing, and effects of N-doping on photoelectrochemical performances were studied. Surfaces morphologies and phase structures were characterized by X-ray diffractometer and scanning electron microscope, while the content and distribution of N in TiO₂ nanotubes were analyzed by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and Raman spectroscopy, respectively. Chronoamperometry was used for measuring the photoelectrochemical performances under UV light and visible light respectively. Researches on the photoelectrochemical detection to organics were conducted by using TiO₂(N) NTAs as photo anode and glucose as model organics. Results show that the photocurrents of all doping samples are increased compared with pristine TiO₂ NTAs, in which the UV photocurrent of optimized TiO₂(N40) NTAs increases from 180.4 μA to 256.8 μA, the detection sensitivity increases from 0.061 μA/(μmol/L) to 0.134 μA/(μmol/L). The enhancing mechanism of the photoelectrochemical performances are studied by analyzing the optical performances, recombination rate of photogenerated carriers and electrochemical performances. Increase of optical response range and effective separation of photogenerated carriers contribute to the enhancement of N-doping TiO₂(N) NTAs' photoelectrochemical performances.

The refractory rare metal molybdenum has the advantages of high melting point (2 620 ℃), good seismic performance and strong corrosion resistance, and has become an important high-temperature structural and functional material, which was widely used in aerospace, semiconductor lighting, microelectronics, medical equipment and other important areas. However, due to a series of processing characteristics such as high temperature oxidation of molybdenum, high deformation temperature, fast temperature drop and high tensile strength, its development is seriously limited in the application field. Molybdenum alloys have excellent thermal conductivity/conductivity, high temperature strength and creep resistance at high temperatures, and are widely used in important high temperature environments such as missiles, turbines and fusion reactor components. In recent years, based on the domestic and foreign scholars′ researches on the mechanical properties of high temperature tensile, compression, creep, bending, fatigue and ablation of molybdenum alloys, it is found that the composition, content and mechanism of different grades of molybdenum alloys have an effect on high temperature performance. In this paper, the future prospects of high-temperature application of molybdenum alloy were reviewed from the practical application point of view, and research and development of new preparation process and performance of molybdenum materials were constructively prospected for the future.

The increasing development of the atomic energy industry has brought about potential safety hazards such as nuclear leakage and nuclear pollution. People must take strict protective measures to protect the health of nuclear facilities staffs and environmental safety. Among the various types of nuclear radiation, neutrons and gamma rays have the strongest penetrability, which are the most difficult to be shielded. However, traditional neutron shielding materials such as boron, water, polyethylene, and gamma-ray shielding materials such as lead, iron, and tungsten have single shielding functions, limited shielding performance, or poor thermodynamic properties, making it difficult to meet modern radiological protection requirements. In this regard, composite materials can combine the advantages of various raw materials which can realize the complementary performance and expand application area of the radiation shielding materials. At present, a large number of composite shielding materials have been developed and applied. According to different substrates, it can be divided into five categories as follow: (1) polymer-based composite shielding materials; (2) metal-based composite shielding materials; (3) shielding concrete; (4) glass-based composite shielding materials; (5) ceramic-based composite shielding materials. In this paper, the mechanism of the interaction between neutrons and gamma rays and atoms is briefly summarized. The research progress of composite shielding materials, and the research content and characteristics of each type of composite shielding materials are detailed reviewed. In addition, the problems to be solved in the current research about composite shielding materials are pointed out and future research trends are predicted.

As an important branch of man-machine interaction, brain-computer interface (BCI) has the potential to be widely used in various fields, such as healthcare, human assistance, aerospace, intelligence traffic system, and entertainment. The flexible electrode is the crucial component of the BCI, and is the key for the development of the BCI technology. Recently, plenty of flexible electrode materials for applications in BCI technology have been developed. In this study, the development of the three kinds of flexible electrode materials in BCI, including non-intrusive electrodes, intrusive electrodes, and semi-intrusive electrodes was reviewed. The challenge and the problems that hinder the development of the flexible electrode materials were analyzed. Besides, the future applications of the flexible electrode materials in the BCI field were prospected.

The development of environmental-friendly and low-cost synthesis methods for electrocatalysts of hydrogen evolution reaction (HER) is of great significance to renewable energy technologies. Here, Ferrocene, polyvinylpyrrolidone (PVP) and urea were used as raw materials to prepared iron carbide/nitrogen-doped carbon (Fe₃C/N-C) composite nanoparticles by simple hydrothermal method and annealing treatment at a certain temperature in this paper. The composition and morphology of the powders prepared under different pyrolysis temperature conditions and their electrocatalytic hydrogen evolution properties were emphatically compared. The results show that Fe₃C/N-C obtained under 800 ℃ had excellent electrocatalytic activity with a relatively low overpotential of only 211 mV at acertain current density of 10 mA/cm²and a small Tafel slope of only 137 mV/dec in alkaline electrolyte, which was superior to other contrastive catalysts. Moreover, Fe₃C/N-C also had good catalytic stability in alkaline electrolyte, which kept its activity at least 10 h. This work gives new insights about the regulation of transition metal carbide and nitrogen-doped carboncomplex construction, and provides technical support for the development of non-precious electrocatalysts which are efficient and inexpensive.

Hexagonal boron nitride (h-BN) material has excellent properties in physical and chemical aspects.Due to its unique morphology and structure, hexagonal boron nitride is of great research value in the fields of thermal conductivity filling materials, carrier materials, adsorption materials, etc, and it is an essential functional material under certain limit conditions in the high-tech field.Therefore, the preparation and properties of hexagonal boron nitridematerials are the focus of current research. In this paper, the basic properties of hexagonal boron nitride were reviewed, some methods for preparing hexagonal boron nitride powder were introduced, the problems in the preparation process were analyzed, and the application development of hexagonal boron nitride powder in the future was studied.

LiPF6, LiBOB and LiPF6/LiBOB blend salt-based electrolytes were investigated for improving cycling performances of LiFePO4/graphite lithium-ion batteries at elevated temperature. It was demonstrated that dissolution of Fe from LiFePO4 was depressed in LiBOB based electrolyte, and columbic efficiency of LiFePO4/Li cell at elevated temperature was increased; LiBOB was reduced earlier on anode surface, forming compact SEI layer; and the capacity retention of LiFePO4/graphite cells at 55 ℃ increases with the LiBOB concentration due to protective depositions of LiBOB on cathode surface and the SEI layer on anode surface, while the impedance of the cell is increased. LiPF6/LiBOB blend salt-based electrolyte combines the advantages of the different salts and maximizes the performance of cells. When electrolytes with LiPF6/LiBOB blend salt was used, the LiFePO4/graphite cells have excellent capacity retention at 55℃, while the impedance was dramatically decreased.

The localized surface plasmon resonance (LSPR) of silver nanoparticles can be varied by adjusting their morphology, size and external dielectric environment. Silver nanoparticles with different morphologies show the localized surface plasmon resonance with different strength, thus demonstrating the unique optical properties. In this review, a variety of silver nanoparticels was prepared via chemical reduction methods, which included citrate reduction method, polyol process method, and seed-mediated growth method. The mechanism and characteristics of these methods were discussed. The research progress of silver nanoparticles with different morphologies in recent years was reviewed. Finally, their applications in the surface enhanced roman scattering (SERS) substrate, antibacterial, and catalysis were introduced, and the future development of silver nanoparticles in synthesis and related application fields was summarized and prospected.

Platinum iridium alloys possess high chemical stability, excellent mechanical and electrical properties, high temperature resistance and high catalytic activity, and have been widely applied in transportation, biomedical, energy, chemical and other fields. In this paper, the typical application fields of platinum iridium alloys were reviewed, such as electrical contact materials, spark plug electrodes, biomedicine, catalysts and etc. The further developing directions of platinum iridium alloys were discussed briefly.

Oleophobic/superoleophobic surface is widely concerned now because of its wide application prospect in the prevention of biological adhesion and oil-resistant materials. In this paper, the related theory of surface wettability and classical physics model were introduced, the preparation and processing methods of oleophobic/superoleophobic surface were summarized, the further research and development were prospected, and the reference for oleophobic/superoleophobic surface to the further research was provided.

With the trend of Moore's law, the decreasing size and fine structure of semiconductor devices, batteries and bio-medical devices increasingly require the higher performance of thermal interface materials (TIMs). The micro/nano structure of these materials will influence the working efficiency and operation life of TIMs. To improve the quality of TIMs, researchers applied new methods on synthesis routine, structure modification, simulation modelling and measurements. In this article, the types of thermal interface materials, for example, single component TIMs, metal-polymer composite TIMs, nonmetal-polymer composite TIMs were summarized. The principle of electron-phonon coupling and its impact on the thermal transport within micro/nano-scale composite materials including lattice vibration, electron-phonon scattering were reviewed. Typical models of electron-phonon coupling like SMAMM was introduced. The equipment and methods such as time domain thermal reflection and 3ω for measuring the interfacial thermal conductance were also introduced, and the development and application of electron-phonon theory in the future was also prospected.

With the rapid development of shape memory composites, polyvinyl alcohol (PVA) based shape memory composites with good biocompatibility are receiving widespread attention. The preparation method of PVA based shape memory composites, such as physical blending methods of solution casting, cyclic freezing and thawing, in-situ polymerization blending, physical embedding, laminating, coprecipitating, and blending followed by supercritical drying and chemical crosslinking methods were introduced. The characteristics and research progress of above-mentioned preparing methods were also discussed in details. The related application research and progress of PVA based shape memory composites on biomedical fields, such as drug sustained release, scaffolds for tissue engineering and photosensor were analyzed and discussed. Finally, it was proposed that the development of PVA based composites with multi-stimulus response and multi-functionality would be the research trend of shape memory composite materials in the future. PVA based shape memory composite materials with excellent comprehensive properties would play an important role in the field of biomedical composite materials.

Lithium-ion batteries are one of the most promising battery systems to be widely used in portable electronics, electric vehicles, and energy storage systems. Lithium titanate (Li₄Ti₅O₁₂) has been intensively investigated as an important anode material for lithium-ion batteries due to its high potential of around 1.55 V (vs. Li/Li⁺) during charge and discharge, excellent cycling stability, and high thermal stability and safety. This paper reviews the recent advances in structure and electrochemical performance of lithium titanate involving on new preparation methods of micro/macro particle, surface modification and ion doping. The micro/macro particles can provide greater surface area and shorten the migration distance for Li⁺. The better contact between the electrode and electrolyte produces benefits transportation of Li⁺, which improves the cycling performance of Li₄Ti₅O₁₂. The major methods of surface modification are carbon coating, forming Li₄Ti₅O₁₂/metal composites and modification by new surface phase. Such methods aim to increase the conductivity and improve the cycling performance of Li₄Ti₅O₁₂. Doping ions increases the electron concentration and electronic conductivity since the partial Ti⁴⁺ transform to Ti³⁺. The future development of lithium titanate as anode materials in lithium-ion batteries is also prospected in this review.

Two-dimensional nano tungsten disulfide has attracted the domestic and foreign researchers for the extraordinary layer structure, tunable gap, stabled physical and chemical properties. The latest progress of the two-dimensional nano tungsten disulfide is summarized, and the crystal structure, optical properties and band structure of the tungsten disulfide are primarily introduced. And then the preparation method of two-dimensional nano tungsten disulfide is listed, and the application of two-dimensional nano tungsten disulfide in the field of photocatalyst, photo detector, lubricant, and field effect transistor is summarized. Eventually, the challenges and opportunities of two-dimensional nano tungsten disulfide are prospected.

The reduction of graphite oxide is the most possible method to achieve mass production of graphene. A number of methods have been developed to exfoliate graphite oxide, and each method has its own advantages and disadvantages. Thermal exfoliation is the most economical way to obtain large quantities of graphene especially functional graphene. The exfoliation mechanism is mainly based on that the sudden expansion gases evolved into the spaces between graphene sheets during the heat-treatment process of graphite oxide. Thermal exfoliation can be realized when the sudden expansion gases pressure overcomed the attractive van der Waals inter-actions between layers. However，different oxidation and reduction processes make the functional graphene with different properties. In this paper, current research is reviewed, the mechanism of the oxidation and thermal exfoliation is discussed, which may contribute us to effectively use the controllable factors to partially control the preparation of functional graphene.

A magnetic biochar (MBC) was prepared by chemical precipitation method with Ginkgo biloba as raw material. The synthesized samples were studied systematically by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and BET surface area. Then MBC was applied to remove Rhodamine B (RB) from wastewater. By simulation experiment, adsorption characteristic of MBC to RB was studied, and the effect of pH value, contact time, initial concentration and adsorbent dosage on adsorption capacity was investigated. The results showed that MBC was an ideal absorbent for RB removal. The iron in the MBC existed in the forms of Fe₃O₄.The maximum removal efficiency reached 99.34% under the following conditions: initial RB concentration of 100 mg/L, MBC dosage of 0.2 g and 120 min. The adsorption kinetic could be well simulated by first order model (R²=0.9914). The results from the intra-particle model also showed that the adsorption process was influenced by both liquid film diffusion and intra-particle diffusion. Adsorption isotherms for MBC were fitted the Langmuir-Freundlich (R²=0.9934) more effectively than other models. MBC is an efficient adsorbent to remove RB from waste water of dye.

Tantalum carbide (TaC) coating was prepared on high-purity, high-density graphite by high-temperature chemical vapor deposition (CVD). The effects of gasification temperatures, flow rates and deposition temperatures on the surface qualities of TaC coating were investigated. And then, the technical conditions of TaC coating prepared by CVD method were confirmed. Finally, TaC coatings with high densities were obtained.

Recently, flexible pressure sensor was an attractive field and had a tremendous application in the field of electronic skin, robots, mobile medical diagnosis and human-machine interaction with the development of carbon nanomaterials. The flexible pressure sensor based on carbon nanomaterials had the advantage of flexibility and stability. In this paper, the classification of flexible pressure sensor based on carbon nanomaterials and the advantages and disadvantages of each type of the flexible pressure sensor were reported. In the end, the development trend of flexible pressure sensor in durability, multi-dimensional deformation detection and biosafety was prospected.

With the development of laser technology, more and more materials can be used to make superhydrophobic surfaces. In order to meet the different needs of self-cleaning, anti-fouling and oil-water separation, different materials need to be selected as the substrates for making superhydrophobic surfaces by laser.The metal substrates are of high hardness, stability and durability, and the superhydrophobic surfaces produced from these substrates are excellent in self-cleaning, anti-freezing and anti-fouling. It is also used to create templates for other superhydrophobic surfaces. Inorganic non-metallic materials have a wide variety of properties, thus the performances of superhydrophobic surface are different. Some of these kind materials have good biocompatibility, some are suitable for oil-water separation and manufacturing of super capacitors. The polymer base has good elasticity, low density and friction resistance, and the superhydrophobic materials made from these substrates can be used in industrial manufacturing and microfluidic devices. This review briefly introduces the basic principle of laser manufacturing superhydrophobic and mainly discussed the common bases of laser manufacturing superhydrophobic surface: the metal base, inorganic nonmetallic substrate and the polymer base. The metal base includes aluminum alloy, stainless and copper. Inorganic nonmetals include quartzcrystals and graphene. The polymer substrate includes PDMS polymer and PTFE. The properties and applications of different superhydrophobic surfaces produced by different bases are described in detail. In the end, the application of superhydrophobic surfaces manufactured by laser is summarized and prospected.

The preparation methods of micro-nano copper powder in the literatures local and overseas are classified and the advantages and disadvantages of different preparation methods are compared in detail. The technical direction of industrialization is pointed out. The main preparation techniques and application characteristics of spherical, dendritic and flaky copper powders are analyzed. The application status and existing problems of copper powder in lubrication, catalysis, conductive materials and engineering structural materials are summarized. Aiming at the bottleneck problem of restricting the application of copper powder like reunion and oxidation, it is hoped that the relevant summary will help the selection and research of materials in related fields.

The gold nano material is prepared by a chemical reduction method, and with sodium citrate as a reducing agent, chloroauric acid is reduced by heating to obtain an aqueous solution of gold nano particles. Using ultraviolet-visible absorption spectroscopy, the influence of preparation process parameters on product size and product generation rate is studied. The results show that the concentration ratio of reactants, the order of reactants and the pH of the solution affect the size of the product to a certain extent, and the holding temperature, holding time and stirring rate have a greater influence on the rate of product formation. Here, the related factors influencing the formation process of gold nanoparticles are analyzed.

As a type of biodegrada polyvinyl alcohol (PVA) film, its environmentally friendly characteristic has been widely recognized around the world. However, its poor water resistance largely limits the popularization and application, due to a large number of hydrophilic groups in PVA molecules. In this work, glutaraldehyde and urea were used to react with PVA by acetal reaction, and then the plasticizers (glycerol, PEG-400, MgCl₂) were added to the system to destroy the hydrogen bonding of PVA and reduce its crystallinity, in order to achieve the plastic modification effect. Finally, the structure of the products and the performance of the cured films were characterized by Fourier transform infrared spectrometer (FT-IR), thermogravimetric (TG) analysis, physical and mechanical properties, and contact angle. The results showed that the water resistance and thermal stability of PVA films could be enhanced by the crosslinking reaction of PVA with glutaraldehyde and urea. The addition of glycerol, PEG-400 and MgCl₂ could improve the elongation at break and tensile strength of PVA films. And when the additive amount of glutaraldehyde, urea, glycerol, PEG-400 and MgCl₂ in the formula were 4%, 0.5%, 6% and 2%, respectively, the mechanical properties of the film were optimal with the elongation at break of 136.7% and the tensile strength of 3.48 MPa.

In recent years, due to the increasing depletion of non-renewable resources, as well as environmental crisis and other issues, the research and utilization of luminescent materials have received widespread attention. As a kind of luminescent material, luminescent fiber has its unique properties. Luminous fiber has many advantages such as non-toxic, harmless, bright color, soft material, excellent anti-aging property, and sustainable luminescence. Luminous fibers are divided into fluorescent fibers and luminous fibers, and luminous fibers are divided into self-luminous type and light-storing type. The luminescent fiber realizes the cycle function of automatically absorbing light-storing light-emitting light. It not only solves the problem of environmental protection but also conforms to the principle of sustainable development. The development of luminous fiber is the need to cope with the scarcity of resources and to realize the sustainable development of the chemical fiber industry. It is also the need to realize energy saving and emission reduction and develop a low-carbon economy. The application fields of luminous fiber materials include but are not limited to luminous printed fabrics, luminous textile applications, toys and embroidered artwork, functional clothing, anti-counterfeiting, and so on. The author sorts out and summarizes the representative results of luminescent fiber materials, mainly including the classification and application of luminescent materials, introduction and preparation methods of luminescent fibers, characteristics and applications of luminescent fibers, and the existing problems and future development of the field. The direction is forecasted.

Due to high melting point, high strength, strong oxidation resistance and deformation resistance at elevated temperature, refractory metal silicides have attracted extensively attention. In the refractory metal silicides, the tungsten-silicon binary compounds, where tungsten has the highest melting point, not only have the similar mechanical and physical properties compared to other metal silicides, but also show many other excellent performance characteristics. The theoretical investigation of tungsten-silicon binary compounds was presented by first-principles calculation to fully exploit the potential performance of tungsten-silicon binary compounds. Two prototype structures of WSi₂ compounds and three prototype structures of W₅Si₃ compounds had been taken into account: α-WSi₂ (C40), β-WSi₂ (C11_b), W₅Si₃-prototype structure (D8_m), Cr₅B₃-prototype structure (D8_l) and Mn₅Si₃-prototype structure (D8₈). The formation enthalpies were calculated to analyze the stabilities, and the elastic constants, bulk modulus, shear modulus, tensile modulus, Poisson’s ratio, anisotropy factor and Vickers hardness were calculated to obtain the mechanical properties. Otherwise, the total and partial density of states were also calculated to obtain the bonding mechanisms of tungsten-silicon binary compounds. The stability calculation indicated that the stability sequence of the five tungsten-silicon compounds forms the following order: β-WSi₂＞α-WSi₂＞W₅Si₃-prototype structure＞Mn₅Si₃-prototype structure＞Cr₅B₃-prototype structure, and the results of density of state further verified it. The calculation results of mechanical properties showed that the five stable phases of WSi₂ and W₅S₃ with good shape, toughness and hardness are agreement with the mechanical stability. Among them, the shape, toughness and hardness of β-WSi₂ are the highest, while those of Cr₅B₃-prototype structure are the lowest. The calculation of elastic constants showed that for α-WSi₂, Mn₅Si₃-prototype structure, W₅Si₃-prototype structure and Cr₅B₃-prototype structure, the bondings along [100] and [010] directions are stronger than that along [001] direction, and the [100](010) shear is easier than [100](001) shear. On the contrary, for β-WSi₂, the bondings along [100] and [010] directions are weaker than that along [001] direction, and the [100](010) shear is similar with the [100](001) shear. The results of total and partial density of states exhibited that the bonding mechanisms of these five compounds are all the mixture of strong covalent and certain metal bonds. In this paper, a new idea and theoretical foundation of new materials based on tungsten-silicon binary compounds will be provided.

SnSe is a new thermoelectric material which just emerges in recent years. Sinceit haslayered structure, very low thermal conductivity and high ZT, it is a prospect of thermoelectric materials for application in the middle and low temperature range. Thus much attention is paid to optimize its thermoelectric performance. In this review, the SnSe’s molecular structure, band structure and transport properties, thermoelectric characteristics were summarized, the advantages and disadvantages of different processing methods were analyzed; the factors which affected its thermal performance and industrial application were discussed. At last we try to put forward to using the advantage of "Mosaic" crystal to optimize the SnSe’s thermoelectric performance. The purpose of this review is to help readers to have a comprehensive understanding of SnSe’s structure, transport properties and thermoelectric characteristics. Meanwhile, for researchers, we aid to provide a possible direction which can improve the SnSe’s thermoelectric performance and search for thermolelectric materials which can gain high ZT.

Spatially nonuniform stresses induced shape deformations represent a powerful tool to fabricate “four dimensional (4D) materials”, which are featured by shape changes on the time scale. Previous experimental methods, however, mainly focus on reversible shape shifts, restricting the applications in the fields of biomedical implants, electronic devices, etc. More importantly, most of these methods suffer from difficulties in reshaping, since the geometric information is defined permanently. Herein, a new kind of self-shaping materials is described to offer both stable three dimensional (3D) shapes and shape reprogrammability by creatively fusing the superiorities of the shape memory polymers and the internal stress induced shape deformations. A pre-strained shape memory polymer Nafion, which was optically transparent, was chosen as the substrate. Black patterns “painted” on the substrate offered spatially heterogeneous light absorption, which heated the substrate locally. As a result, the fabricated materials afforded complicated yet predictable 3D shape transitions. More impressively, the painted patterns and the obtained 3D shapes could be erased by immersion in ethanol and heating, which demonstrated that the materials could be reprogrammed to afford different deformations.

ZnO and ZnO:Cd nanorods were prepared by hydrothermal method. The structure and optical properties of ZnO:Cd nanorods were studied by X-ray diffractometer, scanning electron microscope, UV-Vis-Nir spectrophotometer and Raman spectroscopy. The results show that the sample was a one-dimensional nanorod structure, and Cd doping could reduce the grain size and optical band gap of ZnO nanorods. The photocatalytic degradation efficiency of ZnO:Cd nanorods against azo structure dyes(methyl orange solution) was measured by spectrophotometer. The results showed that Cd doping could improve the photocatalytic degradation efficiency of ZnO, and the photocatalytic degradation efficiency of ZnO:Cd nanorods to methyl orange solution was the highest when the doping concentration was 16%.

Micro arc oxidation of metals and alloys (MAO) involves the interaction between electrolyte and alloy surface at high plasma temperature. In this process, the formation of porous layer on alloy surface is not only closely related to electrolyte composition, but also plays an important role in coating structure and electrical properties. In this paper, MAO of binary Ti Al alloys with different Al content is carried out by adding 0.15 M KOH and 0.1 M Na₂B₄O₇ electrolyte The effect of alloy composition on coating structure in micro arc oxidation process was investigated. Scanning electron microscope (SEM) and 3D laser confocal microscope analyzed the morphology and oxide accumulation thickness of the coating, and contact angle tester measured the hydrophilic properties of MAO coating. The results showed that with the increase of matrix Al content, the MAO process was more intense, which would promote the uniform formation of the coating, increase the hole size, oxide accumulation and voltage value. The coatings show good hydrophilicity, and the increase of Al content makes the coating more uniform, resulting in better hydrophilicity.

Graphene and MXene, as two new two-dimensional materials, have unique structures and properties, such as high conductivity, large specific surface area, light weight, etc., which have been widely concerned and studied in recent years. In particular, the research on MXene with graphene like structure is very popular. In this paper, the structure, absorbing performance and research status of the two materials are compared, and the single material, carbon nanotubes, magnetic particles, conductive polymers and carbon fiber composite materials in the field of electromagnetic absorbing are summarized. In addition, the absorbing mechanism and design principles of the two materials are extracted. It is expected to provide ideas for the research of “thin, light, soft, wide” new electromagnetic absorption materials based on two-dimensional materials.

In this paper, a photocatalytic material of N-doped Cu₂O was prepared by reducing Cu²⁺with hydrazine hydrate. And it was characterized by UV-vis DRS, PL, XRD, XPS and FT-IR. The results indicate that the absorption spectrum of N-doped Cu₂O was blue-shifted, which had slightly wider band gap than pure Cu₂O. The photoluminescence peak produced by light excitation was weaker, which indicated that the photogenerated electron-hole pair produced in the photocatalysis reaction was easier to separate, so that the photocatalytic reaction could be carried out more efficiently. The doping of N inhibited the growth of Cu₂O crystallites, which affected the photocatalytic performance to some extent by changing its structural characteristics. Furthermore, the N-doped Cu₂O samples had excellent visible light photocatalytic activity in the photodegradation experiments of methyl orange simulated wastewater.

High entropy alloys are emerging field in recent years. Different from traditional alloys, they are generally composed of five or more major elements, with the content of each principal element ranging from 5% to 35% (atomic fraction). Many elements are disordered but have simple phase structure. High entropy alloys have obvious advantages and huge development space. Refractory metal based refractory high entropy alloys have great concern in recent years. Refractory metal alloy with three or more high entropy is called refractory high entropy alloys. Due to the high melting point of refractory metal, the refractory high entropy alloys show good high temperature mechanical properties, high temperature oxidation resistance and corrosion resistance, which are welcomed by the mass and expected to replace the traditional high temperature alloy. In this paper, the preparation method, phase structure, mechanical properties, oxidation resistance and corrosion resistance of refractory high entropy alloys are described in detail. Finally, the development of refractory high entropy alloys are prospected.

As an effective substitute for traditional fossil energy, solar cells have attracted wide attention from scholars. As one of the main raw materials of crystalline silicon solar cells, the quality of silver paste affects the photoelectric conversion rate and the levelized cost of energy. Silver powder is the conductive phase in the paste, whose performance plays a key role in the electrical properties, fluidity and adhesion of the paste. In recent years, the research work in the field of silver powder finds that the shape, size, dispersion, particle size distribution and tap density of silver powder have an effect on the electrical properties of conductive paste. Studies have shown that silver powders with different shapes and particle sizes are the main factors determining the properties of paste conductivity and sintering quality. The tap density of the silver powder affects the compactness of the sintered thick film and the photoelectric conversion of the battery. In the preparation of silver powder, the selection of dispersants will affect the dispersibility of the silver powder, thereby affecting the fineness, adhesion and electrical resistivity of the paste.

GO were prepared by Hummers method and ultrasonic dispersion, and the structure of GO was characterized by SEM and FT-IR. The effect on the corrosion resistance of GO with different dosage soaked in complex salt solution respectively for a long period and the wet and dry cycle function on the cement mortar were investigated. The results indicate that the flexural strength, compressive strength and corrosion resistance of cement-based materials reached the maximum after corrosion when the dosage of GO was 0.03%. SEM results show that the internal structure of the reference specimens was partial incompact and rambling and there were obvious corrosion signs inside the cement structure. However, when the dosage of GO was 0.03%, the internal structure of specimens was compact and there weren’t corrosion signs inside the cement structure. The spectrum analysis show that there were many elements such as Na, S, Cl and so on in the reference specimens, but not in the specimens with the dosage of 0.03% GO. The results indicated that it can play a positive role for improving corrosion resistance when the dosage of GO were 0.03% on cement-based materials.